Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
  • A61M5/168—Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D7/00—Control of flow
  • G05D7/01—Control of flow without auxiliary power
  • G05D7/0106—Control of flow without auxiliary power the sensing element being a flexible member, e.g. bellows, diaphragm, capsule
  • G05D7/0113—Control of flow without auxiliary power the sensing element being a flexible member, e.g. bellows, diaphragm, capsule the sensing element acting as a valve
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
  • A61M5/168—Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body
  • A61M5/16877—Adjusting flow; Devices for setting a flow rate
  • A61M5/16881—Regulating valves
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/7722—Line condition change responsive valves
  • Y10T137/7781—With separate connected fluid reactor surface
  • Y10T137/7784—Responsive to change in rate of fluid flow
  • Y10T137/7787—Expansible chamber subject to differential pressures
  • Y10T137/7788—Pressures across fixed choke

Definitions

• the present invention relates to drug delivery systems and. in particular, it concerns a fluid flow regulator for regulating the flow of liquid medications.
• flow regulators have been developed based on the use of a pressure-responsive flexible diaphragm.
• the principle of these regulators may be understood by reference to U.S. Patents Nos. 4,343,305 and 5,421,363 to Dan Bron which are hereby incorporated by reference.
• the Bron '305 reference discloses a flow regulator for use in an infusion set.
• the flow regulator includes a body having a cavity divided into two chambers by a flexible diaphragm. The first of these chambers is a pressure sensing chamber.
• the other is a valving chamber through which the drug flows, the outlet from that chamber being centrally disposed underlying the diaphragm whereby flexing of the diaphragm in one direction as a result of increased pressure in the other chamber adjusts the size of the flow path through the outlet.
• a rudimentary flow impedance adjustment between the two chambers is proposed as a means for adjusting the flow rate.
• the Bron ' 363 reference proposes an improved adjustment configuration in which a tubular flow attenuator fits within the neck portion of a housing.
• the flow attenuator is formed with a pattern of grooves which, together with the opposing surface, define a meander-type labyrinth.
• the relative positions of an inlet and outlet along the labyrinth may be varied by relative rotation between the flow attenuator and the neck portion, thereby changing the operative length of the labyrinth and the consequent flow rate.
• the diaphragm-based regulators of Bron provide significant advantages over the slow-dosing techniques described above. Specifically, these regulators provide generally uniform dosing of medication at low flow rates, thereby avoiding the need for the excessive dilution of conventional infusions.
• the pressure-responsive nature of the regulation also ensures that supply pressure variations are properly compensated. Nevertheless, these regulators suffer from a number of serious shortcomings. Most notably, the full range of adjustment, even for the improved configuration of the '363 patent, corresponds to a range of rotation significantly less than a full revolution. As a result, the regulator is either implemented so as to be limited to a fairly narrow range of flow rates or is overly sensitive to angular displacements offering a low degree of precision in selecting the flow rate.
• the pressure applicator includes an inflatable balloon.
• FIG. 5 is a cross-sectional view taken through a second embodiment of a drug delivery device, constructed and operative according to the teachings of the present invention, including the flow regulator of Figure 1 ;
• fluid flow restriction 22 is formed as an adjustable flow-attenuating passageway at the interface between flow-path-defining component 20 and body component 12 in such a manner that its operative length may be changed by axial displacement of flow-path-defining component 20 relative to body component 12.
• body component 12 provides a first substantially cylindrical outer surface 26, and flow-path-defming component 20 provides a second substantially cylindrical inner surface 28 deployed coaxially, and in sliding contact, with first cylindrical surface 26. At least one of first and second cylindrical surfaces 26 and 28 features at least one groove 30 configured to define a flow-attenuating passageway between surfaces 26 and 28. This flow-attenuating passageway is configured to have a net flow vector substantially parallel to the axis of the cylindrical surfaces.
• Flow-path-defining component 20 and body component 12 are further configured such that relative axial movement between them causes a variation in an extent of overlap between the first and second cylindrical surfaces 26 and 28, thereby varying the operative length of the flow-attenuating passageway.
• the flow-attenuating passageway is described as having a net flow vector substantially parallel to the axis of the cylindrical surfaces.
• the term flow-attenuating passageway as used in the field of fluid flow regulation refers to a structure which produces an artificially elongated flow path between two points. This may be achieved by introducing a meandering flow path (labyrinth) between the two end points or alternatively, in the case of a cylindrical passageway, by producing an elongated helical flow path.
• meandering flow path labeldering flow path
• net flow vector is used herein to denote the net path followed by the fluid from its inlet into the passageway to its outlet therefrom neglecting the '"detours " taken within the passageway itself.
• Groove 30 may be formed on either of first and second cylindrical surfaces 26 and 28, i.e., as part of either body component 12 or flow-path-defining component 20.
• Figures 1-7 employing an example in which groove 30 is formed on surface 26 as part of body component 12.
• Figures 8A and 8B show an equivalent regulator 10'. constructed and operative according to the teachings of the present invention, employing the reverse configuration.
• groove 30 is formed as a helical groove. This has advantages for the ease of manufacture and level of precision with which the groove can be produced.
• more than one groove 30 can be deployed in a double- or triple-helix, although a single helix is generally preferred.
• groove 30 is formed with a variable cross-sectional area in such a manner as to provide sensitivity of adjustment appropriate to the flow rate setting.
• the groove is subdivided into three portions.
• the first portion to come into overlapping relation, designated 30 ⁇ has a relatively large cross-sectional area to provide flow rate adjustment suited to higher flow rates.
• the middle portion, designated 30b, has a smaller area suited to finer adjustments.
• the third portion, designated 30c which only comes into overlapping relation at the lowest flow rates, has a small cross-sectional area to provide the required sensitivity of adjustment at such low rates.
• flow regulator 10 may be configured such that the three ranges correspond respectively to flow rates from 10 liters/hour (1/hr) down to 1 1/hr, from 1 1/hr down to 10 ml/hr, and from 10 ml/hr down to lOO ⁇ l/hr.
• the pressure applicator is employs a spring-loaded piston 54 which is urged forward in relation to an insert sleeve 56 by a helical spring 58.
• the external and front end surfaces of insert sleeve 56 are similar to the corresponding surfaces of adapter 48 described above.
• piston 54 extends from the rear of insert sleeve 56 so as to be manually retractable. This allows manual filling of the storage chamber by retraction of the piston while the front of the dispenser is immersed in the fluid.
• this and other examples of the dispenser may be configured so that diaphragm 14 becomes lifted slightly from seat 42 by the reverse pressure during filling, thereby allowing the fluid flow to bypass flow restriction 22.
• Figure 4 shows a typical application of this dispenser, directly connected to a needle.
• Figures 5, 6 A and 6B show a fluid dispenser similar to that of Figures 3 and 4 in which the spring-loaded piston 60 is implemented as a closed unit not manually retractable. In this case, filling must be done by application of back pressure, such as with a syringe ( Figure 6A). Once full, the syringe is removed and the dispenser may be sealed and stored until required for use. A needle may then be attached ( Figure 6B) for use in the same manner as the previous embodiment.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Hematology (AREA)
• Animal Behavior & Ethology (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Veterinary Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Vascular Medicine (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Automation & Control Theory (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)
• Flow Control (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (1)

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Citations (2)

Family Cites Families (8)

• 1999
  • 1999-11-18 US US09/443,112 patent/US6254576B1/en not_active Expired - Fee Related
• 2000
  • 2000-11-09 AU AU14346/01A patent/AU1434601A/en not_active Abandoned
  • 2000-11-09 KR KR1020027006346A patent/KR20020062644A/ko not_active Application Discontinuation
  • 2000-11-09 IL IL14968400A patent/IL149684A0/xx unknown
  • 2000-11-09 WO PCT/US2000/028893 patent/WO2001036024A1/en not_active Application Discontinuation
  • 2000-11-09 EP EP00976596A patent/EP1233798A4/en not_active Withdrawn
  • 2000-11-09 JP JP2001538013A patent/JP2003513759A/ja active Pending
  • 2000-11-09 CA CA002389540A patent/CA2389540A1/en not_active Abandoned

Patent Citations (2)

Non-Patent Citations (1)

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